1. Field of the Invention
The present invention relates generally to a vibration damping device for use in an automotive engine mount or the like. More particularly, the present invention pertains to a vibration damping device having stopper rubbers in which the stopper rubbers that constitute a stopper mechanism are attached to an outer bracket.
2. Description of the Related Art
Conventionally, vibration damping devices have been known as one type of vibration damping connecting components or vibration damping supports interposed between components that make up a vibration transmission system in order to provide vibration damping linkage between the components, and are employed as an automotive engine mount or the like. This type of vibration damping device includes: a first mounting member to be mounted onto one component of the vibration transmission system; a tubular second mounting member to be mounted onto the other component of the vibration transmission system; and a main rubber elastic body that elastically connects the first and second mounting members. The first mounting member is mounted onto a power unit and the second mounting member is mounted onto a vehicle body via an outer bracket, thereby providing vibration damping support of the power unit on the vehicle body.
Meanwhile, vibration damping devices may employ a stopper mechanism for limiting an amount of relative displacement between the first and second mounting members and preventing excessive deformation of the main rubber elastic body during input of large jarring load. This stopper mechanism is, for example, provided by contact between the first mounting member or an inner bracket attached to the first mounting member and the outer bracket attached to the second mounting member. In addition, a stopper rubber is interposed between the inner bracket and the outer bracket for reducing striking noises during their contact. For example, as disclosed in a vibration damping device having stopper rubbers of Japanese Unexamined Patent Publication No. JP-A-2012-087894, this stopper rubber is fitted onto the outer bracket and positioned so as to cover the contact face of the outer bracket against the inner bracket. This construction generally includes a plurality of stopper rubbers attached to the outer bracket so that the acting load during contact between the inner bracket and the outer bracket is dispersed over the circumference.
However, since the construction disclosed in JP-A-2012-087894 requires the plurality of stopper rubbers separated from each other, there may be an unavoidable problem of increase in the number of components. Particularly with the construction in which the stopper rubbers have mating recesses to be mated with the outer bracket, it is difficult to form the plurality of stopper rubbers in an integral manner. Therefore, it is a general practice to employ the stopper rubbers independent of each other.